Currently, some fluids may contain asphaltenes that may aggregate, flocculate, and deposit. It is known in the industry that asphaltenes may be present in produced petroleum products, such as crude oil, and may cause major problems upon deposition. A sudden change in conditions along the production line of the petroleum product can cause asphaltene to precipitate. Depressurization and/or temperature change often lead to destabilization of the petroleum product, hence asphaltenes may flocculate and deposit. The onset of asphaltene deposit is not necessary dependent on the concentration of asphaltenes, and asphaltene aggregation, flocculation, precipitation and deposition mechanisms are still not fully understood.
Asphaltenes are often defined, not by their chemical functionality and structure, but operationally as those species that can precipitate upon the addition of light petroleum ether like n-pentane and n-heptane, while remaining soluble in aromatic solvents like toluene and xylenes. In general, asphaltenes are defined as polydisperse macromolecules consisting of aromatic rings with alkyl groups of varying lengths with the presence of heteroatoms such as nitrogen, oxygen and sulfur. In addition, metals such as nickel, vanadium and iron may be present as well. Asphaltene molecular weight mass is often accepted as between 500 and 1000 Daltons. Moreover, the carbon to hydrogen ratio is different depending on what petroleum product the asphaltene is isolated from, but usually is found to be 1:1.2. In many cases, the most dominant heteroatom is sulfur, with oxygen and nitrogen as minor constituents. Similar structures as asphaltene (i.e. polycyclic molecules with more aliphatic side-chain character, but in a lower molecular weight range) are defined as maltenes, or simply resins. Different from asphaltenes, this resinous component in petroleum product is soluble in heptanes.
Due to the nature of asphaltenes to flocculate and deposit under a variety of environmental conditions, there is a long felt need to discover and develop effective products, methods and processes to disperse and/or inhibit asphaltene flocculation, precipitation, and/or growth in fluids, such need met, at least in part, by the following disclosure.